1. Technical Field
The present disclosure relates to semiconductor manufacturing apparatuses, and more particularly, to an atomic layer deposition apparatus and to a deposition method thereof for depositing an atomic layer on a semiconductor substrate.
2. Description of the Related Art
Recently, thin film manufacturing process are being precisely controlled below a nano-scale according to the higher integrated tendency of semiconductor devices. The thin film deposition process may thus require a deposition technology more enhanced than the previous physical vapor deposition method and chemical vapor deposition methods. One such technology which may satisfy the above requirement is atomic layer deposition technology.
The atomic layer deposition technology was first introduced in the name of ‘Atomic layer epitaxy technology’ by Suntola of Finland in the mid 1970s. In addition, the above-mentioned atomic layer deposition technology was first applied to a phosphor layer thin film deposition for an electro-luminescent flat display device, but in the '90s the research and development for its application to a semiconductor process is being actively pursued.
The atomic layer deposition technology is a thin film deposition of a new concept using a chemical absorption and desorption through a saturated surface reaction of reaction material on the semiconductor substrate surface by individually separating reaction precursors and flowing them in a pulse type on the semiconductor substrate. Thus, a plurality of reaction precursors can form one layer of thin film during flowing with one cycle on the semiconductor substrate. Further, reaction material flowing on the semiconductor substrate may become three kinds or more. A portion of the reaction materials may be used as a necessary component growing the thin film, and the remaining portions may help a subsequent reaction by removing one or more ligands, thereby processing the substrate surface.
The single-type atomic layer deposition apparatus according to the conventional art, for which an atomic-layer thin film is formed on one semiconductor substrate by using the atomic layer deposition technology, is described in U.S. Pat. No. 6,812,157. But the single-type atomic layer deposition equipment has a low throughput since one semiconductor substrate should be singly provided into a chamber that supplies reaction precursors several times.
Further, to overcome the limitations of the above-mentioned single-type atomic layer deposition apparatus, an atomic layer deposition apparatus of a batch type stacking a plurality of semiconductor substrates has been developed. The atomic layer deposition apparatus of a batch type according to the conventional art is described in U.S. Pat. No. 6,916,374. The atomic layer deposition equipment of a batch type is provided to form respective thin films on the plurality of semiconductor substrates by using reaction materials sprayed through a side face of the plurality of semiconductor substrates stacked in a boat. But in the atomic layer deposition apparatus of a batch type, the thin film formed on the plurality of semiconductor substrates represents a deviation of thickness according to the supply direction of reaction material, thereby decreasing uniformity.
Therefore, in an attempt to solve the above-mentioned difficulty of the batch type atomic layer deposition apparatus in forming a thin film on a plurality of stacked semiconductor substrates through the atomic layer deposition technology, an atomic deposition equipment of a semi-batch type horizontally arraying a plurality of semiconductor substrates is being developed. The atomic layer deposition apparatus of the semi-batch type according to a conventional technology is described in U.S. Pat. No. 6,902,620. But, with the atomic layer deposition apparatus of the semi-batch type, the area of the disc to array a plurality of semiconductor substrates on one horizontal face thereof and a horizontal area of chamber storing the disc may increase. In addition, with the semi-batch type atomic layer deposition apparatus, it may be difficult to control the internal pressure of the chamber and a pollution source such as particles. As a result, the uniformity of thin film may decrease, thereby reducing a production yield.
As described above, the conventional atomic layer deposition equipment may have the following difficulties.
First, in the conventional atomic layer deposition equipment of a single type, throughput decreases as compared with the cost and time taken in performing an atomic layer deposition forming a thin film on one semiconductor substrate within one chamber, and thus the productivity yield may decrease.
Secondly, in the conventional atomic layer deposition equipment of a batch type, the uniformity of thin film based on the flow direction of reaction material sprayed through a side face of a plurality of semiconductor substrates stacked in a boat of a chamber decreases, thereby reducing the production yield.
Thirdly, in the conventional atomic layer deposition equipment of a semi-batch type, there may be a difficulty with the size of disc for supporting a plurality of semiconductor substrates when one plane surface increases and it is also may be difficult to control the internal pressure of chamber and a pollution source. As a result, the uniformity of thin film may decrease, thereby reducing the production yield.